# What is the Integral in Calculus? Explained with Calculations

In calculus, an integral is a mathematical tool that measures the accumulation or total of a quantity, often represented as the area under a curve on a graph. It plays a central role in analyzing continuous change and enables the precise calculation of areas, volumes, and a wide range of mathematical and scientific applications.

Integrals are categorized into definite and indefinite forms, each serving unique purposes in mathematical modeling and problem solving. For solving problems in engineering, economics, physics, and many other fields, making it an essential tool in mathematical modeling and problem solving the concept of the integral is used.

In this article, we will explore the concept of integral in Calculus with the help of definitions, Categories, and laws of integral in calculus. Moreover, with the help of detailed examples and answer integral in calculus explain.

## Definition

An integral in calculus is a mathematical operation that
calculates the accumulated total of a quantity, often represented as the area
under a curve on a graph. It serves as a fundamental tool for measuring and
analyzing the continuous change in various fields of science and engineering.

## Integral in calculus: Types

In calculus, there are two primary categories of integrals:

### ·
Definite Integral:

The definite integral is used to calculate the exact accumulated total of a quantity between two specific points on a function's curve. It yields a single numeric value and represents the net area between the curve and the x-axis over a defined interval.

### ·
Indefinite Integral:

The indefinite integral, often referred to as an antiderivative, calculates a family of functions that, when differentiated, yield a given function. It includes a constant of integration (C) and represents a broader class of functions.

## Laws of Integral in Calculus

In calculus, several fundamental laws and properties run the
manipulation of integrals. Here are some of the key laws and properties of
integrals:

### ·
Linearity of Integration:

In linear terms of integration, the answer to the sum
function integral is always equal to the individual function. In other words, If
a and b are constants and two functions are f(x) and g(x):

∫(af(x)+bg(x)) dx = a∫
f(x)dx +b∫ g(x)) dx

### ·
Constant Multiple Rule:

You can factor constants out of an integral:

∫(af(x) dx = a ∫f(x)
dx

·
__Addition/Subtraction Rule__

∫(f(x)-g(x)) dx = ∫
f(x)dx - ∫ g(x)) dx

This shows that of two functions integral answer is equal to
their integral difference.

· __
____Power Rule for Integration__

The integral of x^{n} concerning x is (n+1)^{-1}x^{(n+1)}
for all real numbers n ≠ -1.

### ·
Integration of Constants:

The integral of a constant is equal to the constant times
the variable of integration:

∫ a dx = ax + C

C= integration constant

### ·
Substitution: Integration

This technique allows you to simplify an integral by making
a substitution, often involving u-substitution.

### ·
Integration by Parts:

Integration by parts is a method for integrating the product
of two functions. It is based on the formula:

∫ udv = uv -
∫ vdu

### ·
Definite Integral Properties:

The definite integral has properties such as the Fundamental
Theorem of Calculus, which relates definite integrals to antiderivatives, and
the Mean Value Theorem for Integrals, which guarantees the existence of an
average value of a function over an interval.

### ·
Change of Limits:

When changing the limits of integration, you need to account
for the effects on the integral. This is important when performing
substitutions or transformations.

### ·
Symmetry Properties:

Some functions exhibit symmetry, which can simplify
integration. For example, even functions have symmetry about the y-axis, while
odd functions have symmetry about the origin.

## Examples

**Example 1:**

Suppose ∫ (2x^{2}+5x-1)
dx simplifies the given expression.

**Solution **

Given data

∫ (2x^{2}+5x-1) dx

Now we solve step-by-step

Step 1: Take the integral of the
constant integral.

∫ 2x^{2}dx=2∫x^{2}dx

The integral of x^{n} is x^{n}+1/n+1 when
n≠−1:

∫ x^{2}dx= 2x^{3}/3

Step 2: Again take the integral
of the constant integral.

∫ 5xdx=5∫x
dx

Take integration we get

∫ x dx= 5x^{2}/2

Step 3:

∫ (−1) dx=−x

Step 4:

Combine all the given results. Then we get.

∫ (2x^{2}+5x-1) dx => 2x^{3}/3 +5x^{2}/2−x +C

For better understanding simplify the expression

∫ (2x^{2}+5x-1) dx = x(4x^{2}+15x−6)/6+C

You can use online calculators like the Integral calculator
offered by MeraCalculator
to solve the problems of integration to get rid of lengthy calculations.

**Example 2:**

∫^{9}_{4} (9x^{2}-3x+10)
dx solve the given integral.

Solution

Given data

∫^{9}_{4} (9x^{2}-3x+10)
dx

Step 1: Take integration and
then put the value of the upper and lower bound.

∫^{9}_{4} (9x^{2}-3x+10)
dx => ∫^{9}_{4} (9x^{2})
dx - ∫^{9}_{4} (3x) dx +∫^{9}_{4} (10) dx

Step 2: Take the value of constant out of the
integration

∫^{9}_{4} (9x^{2}-3x+10)
dx => 9 ∫^{9}_{4} (x^{2})
dx – 3 ∫^{9}_{4} (x) dx
+10 ∫^{9}_{4} (1) dx

Step 3: Now take the integration of the given
function. We get the result.

∫^{9}_{4} (9x^{2}-3x+10)
dx =9 ∫^{9}_{4} (x^{2})
dx – 3 ∫^{9}_{4} (x) dx
+10 ∫^{9}_{4} (1) dx

∫^{9}_{4} (9x^{2}-3x+10)
dx =|3x^{3}−3x^{2}/2+10x|^{9}_{4}

Step 4: Now put the value of the upper and lower bound
we get.

∫^{9}_{4} (9x^{2}-3x+10)
dx = (3(9)^{3}−3(9)^{2}/2+10(9)) −(3(4)^{3}−3(4)^{2}/2+10(4))

Step 5:

Now simplify the result

∫^{9}_{4} (9x^{2}-3x+10)
dx = (4311/2) −(208)

∫^{9}_{4} (9x^{2}-3x+10)
dx = 3895/2

∫^{9}_{4} (9x^{2}-3x+10)
dx = 1947.5

## Conclusion

In this article, we have discussed the definitions,
Categorization, and laws of integral in calculus. Also, for better
understanding we have discussed in this article examples of integral and their
solution. After studying this article anyone can easily defend this article.

## FAQs

### Question# 1:

How does integration relate to differentiation?

**Answer:**

Differentiation and integration are inverse operations in
calculus. If you find the derivative of a function, you can often find its
original function by integrating the derivative.

### Question# 2:

What are some common applications of integrals?

**Answer:**

Integrals are used to calculate areas under curves, volumes
of solids, work done by forces, accumulation of quantities over time, and in
solving differential equations, among other applications.

### Question# 3:

Are there any techniques to simplify integration?

**Answer:**

Yes, techniques such as integration by substitution and integration by parts can simplify complex integrals. Recognizing patterns in functions can also make integration more manageable.